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minio/pkg/event/target/mqtt.go

227 lines
5.8 KiB

/*
* MinIO Cloud Storage, (C) 2018 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package target
import (
"crypto/tls"
"crypto/x509"
"encoding/json"
"errors"
"net/url"
"os"
"path/filepath"
"time"
"github.com/eclipse/paho.mqtt.golang"
"github.com/minio/minio/pkg/event"
xnet "github.com/minio/minio/pkg/net"
)
const (
reconnectInterval = 5 // In Seconds
storePrefix = "minio"
)
// MQTTArgs - MQTT target arguments.
type MQTTArgs struct {
Enable bool `json:"enable"`
Broker xnet.URL `json:"broker"`
Topic string `json:"topic"`
QoS byte `json:"qos"`
User string `json:"username"`
Password string `json:"password"`
MaxReconnectInterval time.Duration `json:"reconnectInterval"`
KeepAlive time.Duration `json:"keepAliveInterval"`
RootCAs *x509.CertPool `json:"-"`
QueueDir string `json:"queueDir"`
QueueLimit uint64 `json:"queueLimit"`
}
// Validate MQTTArgs fields
func (m MQTTArgs) Validate() error {
if !m.Enable {
return nil
}
u, err := xnet.ParseURL(m.Broker.String())
if err != nil {
return err
}
switch u.Scheme {
case "ws", "wss", "tcp", "ssl", "tls", "tcps":
default:
return errors.New("unknown protocol in broker address")
}
if m.QueueDir != "" {
if !filepath.IsAbs(m.QueueDir) {
return errors.New("queueDir path should be absolute")
}
if m.QoS == 0 {
return errors.New("qos should be set to 1 or 2 if queueDir is set")
}
}
if m.QueueLimit > 10000 {
return errors.New("queueLimit should not exceed 10000")
}
return nil
}
// MQTTTarget - MQTT target.
type MQTTTarget struct {
id event.TargetID
args MQTTArgs
client mqtt.Client
store Store
}
// ID - returns target ID.
func (target *MQTTTarget) ID() event.TargetID {
return target.id
}
// send - sends an event to the mqtt.
func (target *MQTTTarget) send(eventData event.Event) error {
objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
if err != nil {
return err
}
key := eventData.S3.Bucket.Name + "/" + objectName
data, err := json.Marshal(event.Log{EventName: eventData.EventName, Key: key, Records: []event.Event{eventData}})
if err != nil {
return err
}
token := target.client.Publish(target.args.Topic, target.args.QoS, false, string(data))
token.Wait()
if token.Error() != nil {
return token.Error()
}
return nil
}
// Send - reads an event from store and sends it to MQTT.
func (target *MQTTTarget) Send(eventKey string) error {
if !target.client.IsConnectionOpen() {
return errNotConnected
}
eventData, eErr := target.store.Get(eventKey)
if eErr != nil {
// The last event key in a successful batch will be sent in the channel atmost once by the replayEvents()
// Such events will not exist and wouldve been already been sent successfully.
if os.IsNotExist(eErr) {
return nil
}
return eErr
}
if err := target.send(eventData); err != nil {
return err
}
// Delete the event from store.
return target.store.Del(eventKey)
}
// Save - saves the events to the store if queuestore is configured, which will be replayed when the mqtt connection is active.
func (target *MQTTTarget) Save(eventData event.Event) error {
if target.store != nil {
return target.store.Put(eventData)
}
// Do not send if the connection is not active.
if !target.client.IsConnectionOpen() {
return errNotConnected
}
return target.send(eventData)
}
// Close - does nothing and available for interface compatibility.
func (target *MQTTTarget) Close() error {
return nil
}
// NewMQTTTarget - creates new MQTT target.
func NewMQTTTarget(id string, args MQTTArgs, doneCh <-chan struct{}) (*MQTTTarget, error) {
options := mqtt.NewClientOptions().
SetClientID("").
SetCleanSession(true).
SetUsername(args.User).
SetPassword(args.Password).
SetMaxReconnectInterval(args.MaxReconnectInterval).
SetKeepAlive(args.KeepAlive).
SetTLSConfig(&tls.Config{RootCAs: args.RootCAs}).
AddBroker(args.Broker.String())
var store Store
if args.QueueDir != "" {
queueDir := filepath.Join(args.QueueDir, storePrefix+"-mqtt-"+id)
store = NewQueueStore(queueDir, args.QueueLimit)
if oErr := store.Open(); oErr != nil {
return nil, oErr
}
}
client := mqtt.NewClient(options)
// The client should establish a first time connection.
// Connect() should be successful atleast once to publish events.
token := client.Connect()
// Retries until the clientID gets registered.
retryRegister := func() {
// Repeat the pings until the client registers the clientId and receives a token.
for {
if token.Wait() && token.Error() == nil {
// Connected
break
}
// Reconnecting
time.Sleep(reconnectInterval * time.Second)
token = client.Connect()
}
}
if store == nil {
if token.Wait() && token.Error() != nil {
return nil, token.Error()
}
} else {
go retryRegister()
}
target := &MQTTTarget{
id: event.TargetID{ID: id, Name: "mqtt"},
args: args,
client: client,
store: store,
}
if target.store != nil {
// Replays the events from the store.
eventKeyCh := replayEvents(target.store, doneCh)
// Start replaying events from the store.
go sendEvents(target, eventKeyCh, doneCh)
}
return target, nil
}